Refrigerating machine indicator



Sept. 15, 1936. v w. HOELLE 2,054,542

' RPilFRIGERAT ING MACHINE INDICATOR I Filed June 21, 1954 2 Sheets-Sheet 1 air 1 'Sept. 15, 1936. L v 2,054,542

REFRIGERATl [NG MACHINE INDICATOR Filed June 21, 1934 2 Sheets-Sheet 2unuunnnm Patented Sept. 1 1936 UNITED. STATES PATENT. OFFICE 3 Claims.

The purpose of this invention is to provide an improved arrangement of.indicating devices responsive to abnormal conditions on the high and lowpressure sides of a refrigerating machine'for 5 indicating the necessityof attention or repairing and to locate failures of individualcooling'coils operated-in multiple from a single compressor unit.

The purpose of the invention is accomplished by means of an arrangementas illustrated in the drawings in which: I

Figure 1 is a diagrammatic view of a refrigerating machine shown, ashaving connections with distantly located cooling coils and arranged tooperate indicating lights on a central panel according to the operativecondition of the machine. The cooling coils also have separateconnections to the indicating panel.

Fig. 2 is an enlarged detail partly in section, showing an expansionmotor operated switch for the compressor motor and contact elements forthe indicator which discloses normal or abv normal operation.

Fig. 3 is an enlarged detail partly in section of an expansion motorwith indicator control contacts and for use in connection with coolingcoils.

In the work of servicing refrigerator machines, it is found that muchneedless expense is occasioned the owners thereof due to delays inlearning of failures of the machines. For instance, a compressing unitmay be locatedin a basement while the cooling coils are on upper floors,and failure of a machine to operate correctly is only learned throughobservation of conditions in the refrigerators. Needless losses areoccasioned due to the lack of a means for indicating at a convenientlocation normal or abnormal conditions in the system.

Dangerous conditions also result from use of refrigerating equipment, asat present manufactured, from many unforeseen possibilities having animmediate eifect upon-'either'the' high or low pressure sides of themachine. Utilization of the pressure conditions is made in the improvedI arrangement for indicating normal or abnormal operation. e

To accomplish the purposes of the invention,

there is provided a central indicating panel having lights wired topressure responsive devices on the high and low pressure sides of therefrigerating machine. Some of the lights are also connected withpressure responsive switches at the individual cooling coils. Thecontacting devices, for these lights indicating the condition of therefrigerating machine, are-arranged to' send a momentary signal for eachnormal operation of the control switch for the compressor motor and tocontinuously signal a failure of the machine. 1 5

Figure 1 shows diagrammatically a refrigerating machine including acompressor I having the usual connections to a condenser 2 andindividual refrigerating coils 3 arranged in multiple. Control switch 4for the circuit 5 of the 10 compressor motor 6 is subject for operationupon the action of an expansion motor -1 having conduit connections 8with the low pressure side of the compressor.

-The expansion device 1 operates a lever 9 piv-'l5 oted at ID andcarries the lever ll linked to the switch 4. The lever H coacts with aresilient quick-throw member l2.

The operation of the lever 9 is in accordance with pressure conditionson'the low pressure side of the compressor and the throwing of switch 4is nicely regulated to occur at some exact pre-" determined pressure byan adjustable spring 13 bearing down upon a plunger I4, resting upon theend of the lever. When the plunger 14 is pressed upwardly against theaction of spring l3, it contacts with-the lower end of a screw l5 whenthe switch is swung to closing position a by action of member I2. 'Thissets'the compressor in operation and there is an immediate drop in thepressure within the expansion motor I and the lever 9 moves slightlydownward, permitting spring actuated plunger M to move out of contactwith screw IS.

The momentary engagement of plunger 14 with screw l5 serves to ground acircuit throughlamp l6 and causes the illumination of the lamp for thatshort interval. Thus anindication is made of the normal operation of theswitch.

7 Screw I5 is carried by an insulator l1 and the conductor [8 leads fromthe screw to lamp i6 and the circuit is from there completed throughconductor l9 to one of the power lines 20. 4 In case the switch 4. isclosed by a rising pressure inthe expansion device I and the motorifails or the compressor I fails tocause a drop in pressure'on the lowpressure side thereof, the lever 9 is-held in its uppermost position andplunger I4 is held in contact with screw 15 and lamp i6 is continuouslyilluminated, thereby indicating failure. of the refrigeration machine.

If an undue pressure occurs on the high pres--- sure side for anyreason, such as lack of circulation or failure of the cooling fluid, anexpansion motor 2| connected by conduit 22 to the high 66 pressure sideof the compressor lifts a plunger 23 carried by the motor into contactwith screw 24. This screw is secured to the insulator guide 25 forplunger 23 and through the conductor 2% is connected with an indicatinglamp 21. The

circuit of the lamp is thus closed through grounding on the plunger 23.

The cooling coils 5 control the operation of signal lamps 29 and 30 andthe lamps are lighted upon undue rise in temperature of these coils. Forthis purpose associated with each coil is an expansion motor M asillustrated in Figure 3. The motor contains an expansible fluid and mmmunicates with a closed tube or bulb 32 filled with the fluid andclamped to the coil 3.

A rise in temperature of the coil ii causes heat to be conducted. to theexpansible fluid. and at a predetermined rise in temperature plunger 33is lifted into engagement with contact screw 36. The screw is carried bythe insulator 35 within which the plunger is slidable. Screw 35 isconnected with a conductor 36 leading to one side of the power line andwhen contact m made the current may flow through the conductor 36, screw34, plunger 33, the irame of the expansion device and by means ofconductor 3? through an indicating lamp back to the opposite side of theline.

In the operation oi the arrangement illustrated, the lamps 29, 3t and 21are normally not illuminated. Also lamp it under normal conditions isonly momentarily illuminated when the switch 4 is thrown to the onposition. This is due to the periodical increase in pressure in theexpansion device '5 at which time the lever d is lifted far enough toengage plunger M with contact screw l5; and as a consequence lamp i6 isilluminated but only until a. drop in pressure on the low pressure sideof the compressor, due to the operation-of the compressor. The arm-isthus drawn downwardly slightly and disengages plunger M from screw i5.But if the compressor fails to operate, the expansion device I remainsexpanded and illumination of lamp it continues.

In case of an undue rise in pressure in the high pressure side of thecompressor, expansion device 25 moves plunger 23 into contact with screw24 and lamp 2'! is illuminated. In case of an undue rise in temperatureof one of the cooling coils 3, the heat therein is communicated to thebulb 32 and the expansion of the fluid therein operates the thermostaticmotor 3|, causing a closing of one of the circuits for lamps 29 or 30,thus indicating what cooling coil is failing to function properly.

.Although but one specific embodiment of this invention is herein shownand described, it is to be understood that details as set forth may,

be altered or omitted without departing from the spirit of the inventionas defined by the following claims.

I claim:

1. A refrigerating machine including a compressor and a condenser, a.motor for driving said compressor, a switch mechanism for the motorincluding a switch, an operating lever and an. expansion motor foroscillating said lever and thereby opening and. closing the switch, saidexpansion motor having conduit connections with the low pressure side ofthe compressor, a separate contact device associated with said lever foroperation thereby to make contact each time the lever comes in positionfor closing the switch,

said lever bemg subject to decreased pressure upon the starting of thecompressor to release f said contact after the closing of the contactand to finally open the switch upon a continued decrease in pressure,said lever and xpwsionmeans also being arranged to hold said contact incontacting position during continued high pressure in the expansiondevice irrespective of the position of the switch operated thereby, an

.motor operated by said expansion motor, an expansion motor connectedwith the high pressure side of the compressor,'contact devices operatedby each of said expansion motors, and indicating means with circuitconnections to said contact devices.

3. In a system of the class described, a refrigerating machine and aplurality of separate cooling units connected therewith, saidrefrigerating machine comprising a compressor and an electric motor fordriving the compressor, a pressure operated switch for said motor, saidswitch being subject to the pressure on the low pressure side of thecompressor, a contact device associated with said pressure-operatedswitch, said contact device being arranged to momentarily move toclosing position each time the pressure operated switch is closed, anindicating circuit connected with said contact device and including alamp; a circuit including an indicating lamp for each cooling unit,means for controlling each cooling unit circuit according to thetemperature of the corresponding cooling unit; a circuit including acontact device and an indicating lamp for indicating the condition ofthe high pressure side of the refrigerating machine, and expansion meansfor operating said contact device, said expansion means being incommunication with the high pressure side of said refrigerator.

WILLIAM HOELLE.

